1. Field of the Invention
The present invention relates to a metallic movement roller that moves a strung endless belt, and to a belt driving device and an image forming device that use such a movement roller.
2. Description of the Related Art
Conventionally, in various fields, an endless belt strung over a plurality of rollers is rotated to transport goods and the like. For example, in an image forming device such as a copying machine, a printer, a facsimile or the like, there are used an intermediate transfer belt for superimposing toner images of a plurality of colors and thereby forming a full color image, a fixing belt that heats toner images in a fixing device, a paper sheet transport belt for transporting a paper sheet which is a transfer member and other components.
Here, the endless belt strung over the rollers is likely to be moved in the direction of the shaft of the rollers depending on conditions such as the inclination and the dimensions of the rollers that are installed. When the endless belt is moved in the direction of the shaft of the rollers, the endless belt moves windingly or obliquely, the endless belt is displaced to one side of the direction of the shaft or its surface become crinkled or wavy. When the endless belt moves windingly or the like as described above, this usually causes a failure of transport of a transport item or poor timing of transport. The endless belt is also likely to be damaged, and this affects the life of the belt.
To overcome these problems, for example, Japanese Unexamined Patent Application Publication No. 2008-139638 proposes a roller in which a grindstone is used to grind the surface of the roller and thus the grinding direction is changed at a predetermined position in the direction of a shaft. This utilizes the fact that tiny scale-shaped splinters are formed obliquely with respect to the direction of rotation on the surface of the roller by grinding and that, when the roller is moved in the direction of the shaft at the time of rotation, a movement resistance force is produced on the endless belt.
However, when a metallic roller is used, even with the processing proposed above, it is impossible to sufficiently reduce the winding movement of the belt and the like.
The present invention is made in view of the conventional problems described above; an object of the present invention is to provide a metallic roller that can reduce the winding movement of a belt and the like to a level enough for practical use.